It's December, which means you are already late on your Christmas cards. If you'll be writing your end-of-year letter on behalf of yourself, your partner, and maybe your kids, start thinking about your return address.

Some words and phrases sound like they should be interchangeable, or are so similar it's hard to tell the difference between. But in the complicated world of English grammar, even these subtle differences can change the entire meaning of a word. Here are 12 common words you need to be careful about mixing up.

Dictionary.com has updated its list of commonly mispronounced English words. We've included them below; along with links to the proper pronunciations.

"The important thing to know about spelling is that it's not just rote memorization," says Ananya Vinay, champion of the 2017 Scripps US National Spelling Bee, who will ceremonially open this year's bee next week. While Vinay uses flashcards to study specific words, she says the real trick is learning where different words come from.

Some grammar mistakes manage to trip up the vast majority of writers. Take "affect" and "effect" -- no matter how many times this grammar rule is explained to people, many writers continue to mix them up. If you're regularly tripped up by homonyms such as "who's vs. whose" and "further vs. farther", this infographic is here to help.

One-star reviews, in addition to being the least helpful kind of review, are also the longest and the worst-spelled. Data journalism blog Priceonomics analysed 100,000 online product reviews and found that 40 per cent of one-star reviews have at least one spelling mistake, vs. under 30 per cent of five-star reviews.

Let's face it: not all of us are cut out to be the next Pulitzer-winning writer, but that doesn't mean we shouldn't write perfectly comprehensible text. Thanks to WhiteSmoke Web, you can keep embarrassing typos, grammatical errors, and stylistic flops out of your work — and subscriptions are on sale for almost 75 percent off.

Little kids spell the darnedest things, am I rit peepl? As a parent, you might have some concern or may even be tempted to get out the red teacher pen, but know that "invented spelling" is perfectly normal, and may even be the key to early reading success.

We all know the rule: "I before E, except after C..." except... uh... something. Good news: You can forget everything except the "I before E" part. And even that will only help you guess correctly three times out of four.

This week, the financial press reported the downfall of a high-profile grammar pedant, Professor Paul Romer, the World Bank’s chief economist, who was hoist(ed) with his own pedantic petard. But 'grammonds' are people to be celebrated not vilified.

Even smart people make stupid mistakes in their writing. Sometimes it’s laziness or impatience; sometimes they’re genuinely confused. Using data from millions of its subscribers, Microsoft recently rounded up a list of the top 10 grammar mistakes in the English language.

Contrary to popular belief, commas don’t just signify pauses in a sentence. In fact, precise rules govern when to use this punctuation mark.

When followed, they lay the groundwork for clear written communication. We’ve compiled a list of all of the times when you need the mighty comma.

Our brains are actually pretty great at filling in gaps, but that's a bad thing when you're scanning for spelling errors. If you want to focus more on each word, you need to put things in reverse.

Love it or hate it, the Comic Sans typeface makes amateur typographers of us all. People don’t normally talk about the fonts they use. Most of us only notice typefaces when they are atypical or inhibit our ability to read. Comic Sans is different. It divides opinion among those who don’t usually identify as typeface enthusiasts.

A split infinitive occurs when an adverb or other word is inserted between 'to' and the verb. One of the most famous examples of a split infinitive is the Star Trek tagline: "to boldly go where no man has gone before." The adverb 'boldly' splits the infinitive 'to go'. Confused? Here are 12 more grammar rules that you might not know; from rogue comma splices to the pitfalls of homonyms.

We all make grammar mistakes from time to time. Usually it's because you're in a rush, writing informally or simply not devoting your full attention to the task at hand. While the odd grammatical snafu is forgivable, there are some errors you definitely need to avoid. This infographic looks at 15 bone-headed stuff-ups that will cause anyone reading to seriously question your intelligence.

"The United States and Great Britain are two countries separated by a common language." So goes the old chestnut commonly attributed to playwright George Bernard Shaw. One of those separations is in the spelling of words like colour (color), theatre (theater), and realise (realize). But how did this separation occur?

There's no such thing as a perfect writer. Even professionals make mistakes from time to time, as our readers never fail to point out. (Thanks for keeping us on our toes, guys!) But some writing errors are so boneheaded and easily avoidable that they infuriate pedants and casuals alike. Here are 10 common screw-ups that every writer needs to avoid, from the embarrassing misuse of homophones to confounding double negatives.

The camps for and against auto-correction are clearly divided. Either you like the extra assistance, or it's nothing short of annoying. I fall into the latter group -- seeing a red line under my mistakes is guidance enough -- but if you prefer blinding typing away with little concern for the rules of language -- and you use Chrome -- an extension called Spell Bee could help you finally break free of your lexical oppressors.